The present invention relates to a system and method for stabilizing the potential slip zone of a slope, and, in particular, to the use of anchored geosynthetic fabrics for effecting slope stabilization.
The problem of soil slope stability is of major importance in almost every part of the world. A variety of natural forces contribute to the deterioration of soil slopes which can result in land slides, mud slides or other slope failures. Slopes comprising granular soils such as gravels, sands and cohesionless silts, are subject to erosion which progressively steepens slope angles until instability occurs. Slopes comprised of fine grained soils, such as silts and clays, often suffer from long term creep movement and stability gradually decreases.
Conventional methods for stabilizing slopes comprise the construction of a retaining wall or a retaining structure, such as shown in U.S. Pat. No. 2,315,351 to Schaefer, to prevent soil displacement. The construction of walls or other rigid or semi-rigid structural barriers is often a very expensive and time consuming undertaking.
Another method for stabilizing slopes is taught in U.S. Pat. No. 3,989,844 to Menard. That patent teaches driving anchors into an embankment and thereafter attaching concrete plates via rods or connecting chains to the anchors to stabilize the embankment. Such a system is also relatively expensive and time consuming.
Geosynthetics are durable, permeable fabrics which are generally classified as either geotextiles or geogrids. Geotextiles, commonly known as construction fabrics or filter fabrics, are made from a variety of synthetic materials such as polypropolene, polyester, nylon, polyvinyl-chloride and polyethylene. They may be woven using monofilament yarns or slit film, or non-woven needled, heat set, or resin bonded fabrics. Geotextiles are available commercially from numerous manufacturers in the United States. Geogrids, also known as geogrid netting, are extruded polyethylene grids with square or rectangular openings from 1/4 to 2 inches wide. Geogrids are distributed in the United States by the Tensar Corporation, Morrow, Ga.
Geosynthetic fabrics, such as geotextiles and geogrids, are used in a variety of both subterranean and surface uses. Some geotextiles are used in road construction to separate a bed of gravel or other material from the underlying earth.
Australian Pat. No. 295,084 discloses the use of geosynthetics to stabilize surface soil. The fabric is staked to the unprotected ground surface which inhibits erosion while grass or other vegetation roots. Such systems, however, do not address the problems associated with major slope failures.